Acetylene generator



March 21,, 1944- w. G. SCHEPMAN ACETYLENE GENERATOR 2 Sheets-Sheet 1 Filed Nov. 28, 1941 INVENTOR MLLAS @arzprmm ATTORNEY March 21, 1944. w. c"; SCHEPMAN AGETYLENE GENERATOR F lled Nov. 23, 1941 2 Sheets-Sheet 2 INVENTOR zz/jfa/ipmqm ATTORNEY Ilfllllll Patented Mar. 21, 1944 2,344,564 acsrnnm: GENERATOR Willis G. Schepmnn, Indianapolis, Ind., assignor to Union Carbide and Carbon Corporation, a corporation oi New York Application November 28, 1941, Serial No. 420,746

19 Claims.

This invention relates to acetylene generators, and particularly to relatively small capacity, portable, low pressure or medium pressure generators of the carbide-to-water type.

An object of this invention is to provide a relatively small capacity, light-weight, inexpensive, portable acetylene generator which possesses operating and safety characteristics equivalent to those of relatively large generators. Other objects include the provision of such a generator in which pressure-responsive mechanism is provided for opening and closing the carbide feed valve in accordanc with variations of acetylene pressure within the generator and including manually operable means for closing the carbide feed valve independently of the effect of such pressure-responsive mechanism; the provision of such a generator including a carbide feed valve adapted to close automatically when the pressure-responsive mechanism fails to function, or when the connection between the valve and the pressure-responsive mechanism is broken; the provision of such a generator including a carbide feed valve adapted to be located positively in a closed, starting, and operating position; the provision of such a generator including a carbide feed valve adapted to close automatically in the event acetylene is withdrawn from the generator faster than it can be generated safely; the provision of such a generator in which a combined carbide hopper and feed control unit is threadedly connected to the gas generating tank and in which simple but effective interference mechanism is provided for insuring the release of gas pressure within the generator before such unit can be disconnected from or reconnected to the tank; the provision of such a generator in which the combined carbide hopper and feed control unit, including a carbide feed valve, is threadedly connected to the gas-generating tank, means being provided for insuring that the carbide feed valve is closed before such unit is disconnected from the tank;

- and the provision of such a generator including means for inhibiting water within the gas generating tank from splashing onto the carbide feed valve and for inhibiting the formation of encrustations of lime hydrate about the carbide feeding apparatus.

Other objects and novel features of the invention will becomeapparentfrom the following specification considered in the light of the accompanying drawings, in which:

Fig. Us a front elevation of an acetylene generator embodying the principles of this invention;

Fig. 2 is an enlarged view, principally in section, of the upper portion of the generator shown in Fig. 1, and taken along the line 22 looking in the direction of the arrows; and

Fig. 3 is an enlarged side elevation of the feed control housing of Fig. 1.

The invention is shown in the drawings as applied to an acetylene, generator of the carbideto-water type, comprising a tank '1 having an opening at its upper end, and adapted to contain water in its lower portion and to confine acetylene thereabove. Referring to Fig. 2, a tubular nipple N, having a threaded upper portion, is fitted within the opening at the upper end of the tank and is firmly attached thereto as by welding, the lower portion of the nipple extending down into the tank. A combined carbide hopper and feed control unit U is removably connected to tank T by threaded engagement of the nipple N with a collar C, which latter is welded to the bottom of hopper H. As employed throughout the specification and claims, the words threaded and threadedly ale to be understood to describe not only the usual type of threaded construction, but also any construction whereby a joint between two members may be broken by rotating or turning one member with respect to the other. An opening is provided in the bottom of the hopper for delivering carbide into the tank, such opening being controlled by a carbide feed valve V. A filter unit F, provided with a removable cover plate and replaceable filtering elements, is fitted into the top of the tank, and a pipe P conducts acetylene from the filter to a hydraulic back-pressure arrestor D located on the outside of and attached to tank T. The back-pressure arrestor D includes a regulator E for controlling the pressure at which gas is fed into the service line. A service connection S, an automatic pressure relief poppet type valve R1, and a pressure gauge G1 are connected to pressure regulator E and communicate with the delivery chamber thereof. An automatic pressure relief poppet type valve R: and a pressure gauge G: are connected to the top of tank T and communicate with the acetylene-confining chamber within the tank.

As shown in Fig. 1, the gas generating tank T comprises a substantially cylindrical shell I closed at its bottom by a base 2 and provided with a shoulder plate 3 at its upper extremity. The tank is equipped with carrying handles 4, a water overflow plug 5, a residue drain'valve 6,

and a sludge agitating paddle mounted on a shaft 1 which is journaled in diametrically opposite bearings located in the shell I. One of the bearings is in the form of a packing gland 8 for accommodating one end of the shaft 1 which extends outside of the shell I and is bent to form a handle 8 for operating the sludge agitating paddle.

The carbide hopp er H, which is closed at its top by a diaphragm l0, comprises a sheet metal body II having an inverted frusto-conical lower portion which tapers to the carbide feed opening in the bottom of the hopper. A feed control housing l2 having a central dome l3, overlies the diaphragm I II and is secured to a flange l4 of the hopper body II by bolts and nuts IS, the flange l4 being reinforced by a channeled reinforcing ring l6. The periphery of the diaphragm I is secured gas-tightly between the hopper flange l4 and the flange portion of the feed control housing. The collar C surrounds the carbide feed opening in the hopper and is welded to the sides of the hopper adjacent the opening. A hook I! is attached to the outside of the hopper so that when the unit U is disconnected from the nipple N, it may be supported in an inverted position by hanging the hook over one of the tank handles 4, as shown in dot-and-dash lines in Fig. 1.

Referring again to Fig. 2, a spring cup I6 is connected to diaphragm III by a bolt I9 which passes through two washers 20, the bottom of the cup, a. diaphragm plate 2|, and the diaphragm l0, and threads into a diaphragm yoke nut 22, centrally positioned on the under side of the diaphragm. In this manner, the cup is mounted on the diaphragm for free rotation with respect thereto when the cup is engaged by manually operable means to be described later for raising the cup and diaphragm against the pressure of a spring 23 to close the carbide feed valve V. Rubber cement or other sealing material is used to obtain gas-tight joints between the under surface of the diaphragm plate 2| and the upper surface of the diaphragm, and between the upper surface of the yoke nut 22 and the under surface of the diaphragm.

The carbide feed valve V comprises a carbide feed valve rod 24, having an annular V-shaped notch 25 formed near the lower end thereof above a closure portion 24 of the rod, and adapted to cooperate with a central opening in a removable valve seat member 26 for controlling the flow of carbide into the water in tank T. The rod 24 is pivotally connected to yoke nut 22 by a cotter key 21 which is received in holes bored through rod 24 near the upper end thereof and through arms 28 of the yoke nut. Such construction permits the rod 24 to move laterally as well as longitudinally within the carbide hopper, thus preventing the rod from being jammed by pieces of carbide as it moves within the carbide feed opening in valve member 26. A lug 29 is formed on the rod 24 above the notch 25 so that the rod will occupy the opening in the valve seat 26 in the event that the rod breaks or becomes disconnected from the diaphragm. Pressure responsive mechanism for controlling the operation of the carbide feed valve comprises the diaphragm l0 and the spring 23 which is seated in the cup I 8 and provided at its upper end with an adjusting cap 30. An inwardly extending boss 3|, formed integrally with the top of housing dome I3, is internally threaded to receive a slotted set screw 32. By adjusting this set screw, the force exerted on the diaphragm III by the spring 23 in opposition to the presure within the generator may be regulated to establish the pressure at which it is desired to produce acetylene within the generator. A cover bolt 33 is provided for closing the threaded opening in the top of the housing dome l3.

The valve seat 26 is removably held within the collar C by a bayonet type connection. Referring to Fig. 2, a pair of vertical grooves (not shown) and a pair of horizontal grooves 34, each connecting with one of the vertical grooves, are formed in the inner wall of a shoulder 35 of collar C. A pair of lugs 36 are formed integrally on the outer surface of the upper portion of valve member 26 and in a position for with the vertical grooves in collar 0. With the combined carbide hopper and control unit U supported in its inverted position by means of the hook H, the valve member 26 may be inserted within or withdrawn from collar 6 by positioning such member so that the lugs 36 register with the vertical grooves formed in. the collar. When the valve member 26 has been so inserted, it. may be locked within the collar C by rotating it so that the lugs 36 travel to the closed ends of the horizontal grooves 34. With the valve member26 removed from the collar 0, the rod 24 may be moved to one side, and the hopper H charged with carbide through the resultant opening. A tubular extended portion 31 of the valve member 26 provides a handle by means of which such valve member may conveniently be held while it is being inserted within or withdrawn from collar C. An annular gasket 38, which hits tightly around the tubular valve member 26 under a shoulder formed thereon at the upper end of the portion 31, provides a gas-tight seal between nipple N and collar C and also serves to hold the member 26 within collar 0 in the event that such member is accidentally turned so that lugs 36 register with the vertical grooves in the collar.

With the combined hopper and control unit U operably connected to tank '1', as shown in Fig. 2 the tubular portion 31 of member 26 extends within the nipple N down into tank T and cooperates with the nipple to inhibit splashing of water onto the carbide feed valve V. By the arrangement of member 26 within the tubular nipple N and by reason of the insulation of such member from the nipple N and from the temperature outside of the generator by means of the gasket 38 and the joints between the member 26 and collar 0, the water vapor present within the nipple N tends to condense on the inner surface thereof rather than on the sin-faces of member 26, since such member will be warmer than the nipple N. Hence, carbide which is guided into tank T through the inner tubular member 26 encounters only a negligible amount of condensed moisture about the lower edge of such member, and is prevented from coming into contact with the moisture which collects on the lower edge of the outer tubular member or nipple N, thus reducing to a minimum the formation of encrustations of lime hydrate about the carbide feeding apparatus.

The underside of diaphragm I6 is subjected at all times to the pressure of acetylene within the generator even though the carbide feed valve V is closed (as shown in Fig. 2), because there is suflicient space between the periphery of rod portion 24' and the cooperating edges of the opening in the valve seat 26 to maintain gaseous communication between hopper H and tank T. Such space, however, is not sufficient to permit granular carbide, which is preferably used in the generator, to flow therethrough. When sufficient pressure is exerted on the underside of diaphragm III to overcome the force of spring 23, the diaphragm Ill and valve rod 24 move upwardly so that the portion 24' of the rod-closes the carbide feed' opening in valve seat 28. As

' the pressure within the generator decreases due to acetylene being drawn oil through the service line, the diaphragm and valve rod gradually fall and the carbide feed valve V opens. Carbide is then fed into the water in tank T until suiilcient pressure is again established within the generator to raise the diaphragm enough to close the carbide feed valve. In this manner the pressure of acetylene within the generator is maintained at a substantially constant value. Although the pressure at which the acetylene is generated corresponds to the pressure for which spring 23 is adiusted, the regulator E controls the pressure at which gas is fed into the service line. The pressure regulator E is of the spring-loadeddiaphragm type, having a stem type valve for controlling the flow of acetylene through a passage between the top of the back-pressure arrestor tube and the delivery chamber of the regulator. A screw 39 is provided for adjusting the pressure exerted on the diaphragm by the spring of the pressure regulator.

The width of the V-shaped notch 25 and its position on the valve rod 24 is such that in the event the underside of diaphragm I is subiected to insuiiicient pressure to maintain at least part of the notch 25 within the opening in the valve seat 26, so that the valve V is at least partly open, a portion of the rod 24 above the upper edge of notch 25 will occupy the opening in the valve seat. With the diaphragm l0 and valve V so constructed and arranged, the flow of carbide into the water in tank T is positively terminated in case the diaphragm I0 is ruptured. Such construction also prevents operation of the generator above its rated capacity, since the diaphragm III will fall to a position in which a portion of the rod 24 above the upper edge of the notch 25 occupies the opening in the valve seat 26, if the regulator E and the valve in the service connection S are adjusted to deliver more acetylene than the generator can safely produce.

The manually operable means previously referred to for raising the cup l8 and diaphragm ill against the pressure of spring 23 to close the carbide feed valve V, comprises rotatable means such as an annular ring 40 surrounding the spring cup l8, and a pair of operating handles 4| threadedly attached to the ring at diametrically opposite positions. The handles 4| extend through inclined slots 42 formed in the vertical side walls of the housing dome l3 and are provided with bearings 43 which are adapted to engage the lower surfaces of slots 42 and thereby support ring 43. By rotating the operating handles 4| in a counterclockwise direction about the vertical axis of the spring cup l8, they travel up the inclined slots 42 and thereby raise the ring 40. As the ring is thus raised, it engages the underside of the cup lip 44, thereby lifting the cup l8 and the diaphragm l0 against the force of spring 23 to position the valve rod portion 24' in the opening in valve seat 25, thus closing the carbide feed valve V. Minimum frictional resistance to rotation of the handles 4| about the vertical axis of the cup I8 is insured by connecting the cup to the diaphragm ||I for free rotation about its vertical axis with respect to the diaphragm by means of the bolt, washer, and nut assembly, as previously described, and by providing smooth bearing surfaces between adjusting cap 30 and the bottom of set screw 32, and between cup lip 44 and lifting ring 49. As shown in Fig. 3, a slight reverse incline 4 5 is formed at the upper portion of each slot 42, thus providing means for locking the operating handles and carbide feed valve in the closed position. When the handles 4| are manually rotated to the top of the inclined slots 42, they seat in the reverse inclines 45 and are thereby prevented from travelling back down the slots when released.

By the application of counterclockwise force to the handles 4| when seated in the reverse inclines 45, the combined hopper and control unit U may be turned about its vertical axis and thereby threadedly disconnected from nipple N. As the unit is so turned, the hook I! on the side of the carbide hopper engages lever means such as a cam lever 46 which is pivotally connected to the top of the valve stem of relief valve Re. A similar cam lever 46' is provided on relief valve R1, and is connected to lever 46 by a pivotally mounted rod 41. Continued turning of the unit U about its vertical axis moves the levers 46 and 46' and the rod 41 to the posi- .tion shown in dot-and-dash lines in Fig. 1, thus opening relief valves R1 and R2 and moving the lever 46 out of the path of hook l1. 5 The arrangement and construction of hook l1, manually operable levers 46 and 4G, and manually operable rod 41 provides simple but effective interference mechanism for insuring the release of pressure within tank '1' and backpressure arrestor D before the gas-tight seal between tank and hopper is broken and before the hopper and control unit U can be disconnected from or reconnected to the gas generating tank. Furthermore, the inclination of the slots 42 in the direction shown in the drawings assures that the carbide, feed valve V will be closed when the operating handles 4| are rotated in the direction for disconnecting the hopper and control unit from the generating tank.

After the hopper H has been filled with carbide and the valve member 25 inserted in collar C, as previously described, tank T and back-pressure arrestor D are filled with water to the proper levels, and the combined hopper and control unit U is threaded onto the'nipple N. The rod 4'I'is'then moved to close the relief valves R1 and R2 and the handles 4| are lifted out of the reverse inclines 45 and allowed to travel about halfway down the inclined slots 42 to a position marked startin on the feed control housing. With the operating handles manually held in -this starting position, the deepest portion of the annular V-shaped notch 25 lies in the carbide feed opening in member 25 and the carbide feed valve is fully open, thus permitting carbide to flow into tank T rapidly. As soon'as the desired operating pressure is established in the generator, the handles 4| are released and travel down the slots 42 to the normal operating" position at the lower ends thereof. With the handles 4| in the operating posltion, the lifting ring 40 is disengaged from the cup lip 44 so that the full force of the spring 23 is exerted downwardly on diaphragm III, and feeding of carbide into tank T is controlled by the pressure-responsive mechanism as previously described.

After recharging the generator with water and carbide it is desirable to purge it of the air-acetylene mixture which will-be formed when generation is first begun. With the desired pressure established in the generator, the handles II are moved up the slots 42 to the closed position, thus closing the carbide feed valve V. By moving rod 41 toward the position shown in dot-and-dash lines in Fig. 1, relief valves R1 and B: may be slowly opened until gauges G1 and G2 indicate only a slight super-atmospheric pressure. Valves R1 and R2 are then closed and the operating handles are moved to and held in the starting position so that carbide is fed into tank T until the desired operating pressure is again established within the generator.

Although the various features of the invention' have been described in detail to disclose fully one embodiment thereof, it will be understood that various modifications of the disclosure may he made and that certain features thereof may be employed without others, without departing from the principles of the invention.

I claim:

1. In a combined carbide hopper and feed control unit for an acetylene generator in which the flow of carbide out of the hopper is controlled by a carbide feed valve connected to a diaphragm which is subject on one side to the pressure of acetylene within the generator, the combination of a spring cup connected to the other side of said diaphragm, a spring seated in said cup and acting against said other side of said diaphragm in opposition to the pressure of acetylene within the generator, and means engageable with said cup, rotatable about the vertical axis thereof, and adapted to raise said cup and said diaphragm against the force of said spring, thereby to close said carbide feed valve.

2. Apparatus as claimed in claim 1, and including means associated with the rotatable means for locking said feed valve in its closed position.

3. Apparatus as claimed in claim 1, in which said cup is connected to said diaphragm in such a manner than it is free to rotate about its vertical axis with respect to said diaphragm.

'4. An acetylene generator comprising a tank adapted to contain water and having an opening in the top thereof; a carbide hopper connected to said tank and having an opening in the bottom thereof; a carbide feed valve for controlling the flow of carbide from said hopper through such openings into the water in said tank; pressureresponsive mechanism including a diaphragm subject on one side to the pressure of acetylene within the generator and adapted to open and close said carbide feed valve in accordance with variations of acetylene pressure within the generator; a spring cupconnected to the other side of said diaphragm; a spring seated within said cup and acting against said diaphragm in opposition to the pressure of acetylene within the generator; and means engageable with said cup, rotatable about the vertical axis thereof, and adapted to raise said cup and said diaphragm against the force of said spring, thereby to close said carbide feed valve independently of the effect-of said pressure-responsive mechanism.

5. An acetylene generator comprising a tank adapted to contain water and having an opening in the top thereof; a carbide hopper threadedly connected to said tank and having an opening in the bottom thereof; a carbide feed valve for controlling the flow of carbide from said hopper through such openings into the water in said tank; rotatable means for closing and opening said carbide feed valve, said means being so constructed and arranged with relation to said hopper that continued rotation thereof in the direction for closing said carbide feed valve, after said valve has been closed, efiects disconnection of said hopper from said tank.

6. A combined carbide hopper and feed control unit for an acetylene generator, comprising an inverted frusto-conical hopper having a carbide feed opening at its lower end; a diaphragm forming the top wall of said hopper and subject on one side to the pressure of acetylene within the gen-' erator; a carbide feed valve connected to said diaphragm and adapted to control the flow of carbide through said carbide feed opening in response to movements of said diaphragm; a feed control housing covering said diaphragm and having a central dome; a-spring cup connected to the side of said diaphragm within said housing; a. spring seated within said cup and acting against said diaphragm in opposition to the pressure of acetylene within the generator; an annular rotatable ring surrounding and adapted to engage said cup; a pair of handles connected to said ring at diametrically opposite positions, each of said handles extending through an inclined slot formed in the side wall of the housing dome and being provided with bearings adapted to cooperate with the lower surfaces of such inclined slots so that said handles travel up said inclined slots readily as they are inverted frusto-conical hopper having a carbide feed opening at its lower end; a diaphragm forming the top wall of said hoppenand subject on one side to the pressure of acetylene within the generator; a carbide feed valve connected to said diaphragm and adapted to control the flow oi carbide through said carbide feed opening in response to movements of said diaphragm; a feed control housing covering said diaphragm and having a central dome; a spring within said housing and acting against said diaphragm in opposition to the pressure of acetylene within the enerator; and means rotatable about the axis of said control housing dome for raising said diaphragm against the action of said spring, said means comprising a pair of handles respectively extending through inclined slots formed in the side wall of the housing dome at diametrically opposite positions, and being providedwith means adapted to cooperate with the lower surfaces of such inclined slots so that said handles travel up said inclined slots readily as they are turned about the vertical axis of said central housing dome, thereby causing said diaphragm to close said carbide feed valve, the upper portion of each of said inclined slots being formed with a reverse incline so that said handles may be positioned therein to lock said handles and said carbide feed valve in the closed position.

8. A combined carbide hopper and feed control unit for an acetylene generator having a tank, said unit cnmnri ina an a-mmama c-mhopper having a carbide feed opening at its lower end; a diaphragm forming the top wall of said hopper and subject on one side to the pressure of acetylene within the generator; a carbide feed valve connected to said diaphragm and adapted to control the flow of carbide through said carbide feed opening in response to movements of said diaphragm; a feed control housing covering said diaphragm and having a central dome; a spring within said housing and acting against said diaphragm in opposition to the pressure of acetylene within the generator; and means rotatable about the axis of said central housing dome for raising said diaphragm against the action of said spring, said means comprising a pair of handles respectively extending through an inclined slot formed in the side wall of the housing dome at diametrically opposite positions, and being provided with means adapted to cooperate with the lower surfaces of such inclined slotslso that said handles travel up said inclined slots readily as they are turned about the vertical axis of said central housing dome, thereby causing said diaphragm to close said carbide feed valve, said carbide hopper and feed control unit being threadedly connected to said tank, and the direction of rotation of the rotatable means being such that continued rotation thereof about the vertical axis of said cup in the direction for closing said carbide feed valve, after said valve has been closed, effects disconnection of said hopper and control unit from said tank.

9. An acetylene generator, comprising a tank adapted to contain water in its lower portion and to confine acetylene thereabove; a carbide hopper rotatable relative to said tank; cooperating threads on said hopper and tank operable upon relative rotation of said hopper and tank whereby said hopper is threadedly connected to said tank and forms a-gas-tight seal therewith; automatic pressure relief means for relieving excessive pressure within said generator; lever means connected to said relief means for operating said relief means from outside said generator; and means attached to said hopper and adapted to operate said lever means to relieve the pressure within said generator as said hopper is rotated, and thereby threadedly disconnected from said tank and prior to breaking said gas-tight seal.

10. An acetylene generator, comprising a tank adapted to contain water in its lower portion and to confine acetylene thereabove; a hydraulic back-pressure arrestor connected to said tank and communicating with the acetylene confining space within said tank; a carbide hopper threadedly connected to said tank; two pressure relief valves respectively connected to said tank and to said back-pressure arrestor for relieving excessive pressure therein; lever means, including a separate cam lever operatively connected to each of said relief valves and a rod connecting such cam levers, for opening and closing said relief valves;

. and means attached to the outside of said carbide hopper and adapted to engage and operate said lever means to open said relief valves as said hopper is threadedly disconnected from said tank.

11. An acetylene generator, comprising a tank adapted to contain water in its lower portion and to confine acetylene thereabove; a hydraulic backpressure arrestor connected to said tank and communicating with the acetylene confining space within said tank; a carbide hopper threadedly connected to said tank; a carbide feed valve for controlling the flow of carbide from said hopper into the water in said tank; and rotatable means for turning said hopper to threadedly disconnect it from said tank. said rotatable means and said carbide feed valve being so constructed and arrangedthat said valve is locked in its closed position by moving said rotatable means in'the direction for disconnecting said hopper from said tank; two pressure relief valves respectively connected to said tank and to said back-pressure arrestor for relieving excessive pressure therein; means operatively connected to each of said relief valves for opening and closing said relief valves; and means attached to the outside of said carbide hopper and adapted to engage and operate said means to open said relief valves as said hopper is threadedly disconnected from said tank.

12. An acetylene generator, comprising a tank adapted to contain water in its lower portion and to confine acetylene thereabove; a hydraulic backpressure arrestor connected to said tank and communicating with the acetylene confining space within said tank; a carbide hopper threadedly connected to said tank; two pressure relief valves respectively connected to said tank and to said back-pressure arrestor for relieving excessive pressure therein; means operatively connected to each of said relief valves for opening and closing said relief valves; a hook attached to the outside of said carbide hopper by means of which said hopper may be supported when disconnected from said tank, said hook being adapted to engage and operate said means to open said relief valves as said hopper is threadedly disconnected from said tank.

13. An acetylene generator comprising a tank having an opening in its upper end, and adapted to contain water in its lower portion and to confine, acetylene thereabove; a carbide hopper connected to said tank and having a carbide feed opening in its lower end, said hopper being provided with an inner tubular member extending from said carbide feed opening down into said tank for delivering carbide into the water contained therein; an outer tubular member spaced from and surrounding said inner tubular memher and extending down into said tank, a gasket cooperating with said inner and outer tubular members and the spacing and enclosure thereof whereby said inner tubular member is insulated from said outer tubular member and from the temperature outside the generator in such a manner that substantially all the water vapor within said outer tubular member condenses thereon so that the carbide passing through said inner tubular member encounters substantially no condensed moisture on said inner tubular member, whereby the formation of encrustations of lime hydrate about said tubular members is substantially prevented. a

14. An acetylene generator as claimed in claim 13, in which said outer tubular member comprises a tubular nipple attached to said tank and extending through the opening in the upper end thereof, and by means of which said hopper is connected to said tank.

15. In a combined carbide hopper and feed control unit for an acetylene generator in which the flow of carbide out of the hopper is controlled by a carbide feed valve connected to a diaphragm which is subject on one side to the pressure of acetylene within the generator and on the other side to the pressure of a spring, the

for raising said diaphragm against the pressure said diaphragm to release said diaphragm from said manually operable rotatable means and to permit said valve to operate in response to pressure variations within the generator, said manually operable means and said valve being so constructed and arranged that said means may be positioned so that said valve is held in its fully open position, whereby carbide may flow out of said hopper rapi ly.

' 16. An acetylene generator comprising a tank adapted to contain water and having an opening in the top thereof; a carbide hopper connected to said tank and having a carbide feed opening in the bottom thereof; a carbide feed valve rod hav ing a notch formed therein near the lower end and adapted to cooperate with said carbide feed opening for controlling the flow of carbide from said hopper into the water in said tank; pressureresponsive mechanism including a diaphragm for actuating said carbide feed valve rod in accordance with variations in acetylene pressure within the generator, and means rotatable about the vertical axis of said rod for raising said rod and reversely rotatable for releasing said rod from said rotatable means thereby to permit actuation of said rod by said diaphragm, said pressureresponsive mechanism and said rod being so constructed and arranged that a portion of said rod other than that in which said notch is formed occupies said carbide feed opening in the event that said diaphragm is subjected to pressure insuflicient to raise said diaphragm enough to position saidnotch at least partly within said carbide feed opening. Y 7

17. An acetylene generator comprising a tank I having an opening in the top thereof, and adapted to contain .water in its lower portion and to conflne acetylene thereabove; a carbide hopper connected to said tank and having an opening in the bottom thereof; a carbide feed valve for controlling the flow of carbide from said hopper through such openings into the water in said tank; pressure-responsive mechanism including a diaphragm operatively connected to said carbide feed valve and subject on one side to the pressure of acetylene withinthe generator and on the other side to the pressure of a spring, and manually operable means for closing said valve, said manually operable means being reversely operable to release said valve and thereby to permit said pressure-responsive mechanism to open and close said carbide feed valve in accordance with pressure variations within the enerator free of said manually operable means, said pressure responsive mechanism being operable, when reand so constructed and arranged with relation to said carbide feed valve that said valve is closed when the pressure of acetylene within the generator is sumcient to overcome the force exerted on said diaphragm by said spring, and so that said carbide feed valve is also closed when the pressure of acetylene within the generator is insufllcient to raise the diaphragm enough to open said valve at least partly.

I8. In a combined carbide hopper and feed control unit for an acetylene generator in which the flow of carbide out of the hopper is controlled by a carbide feed valve connected to a die.- phra'gm which is subject on one side to the pressure of acetylene within the generator, a feed control housing covering said diaphragm, said housing having slots, a spring acting against said diaphragm in opposition to said pressure, means rotatable about the vertical axis of said diaphragm for raising said diaphragm against the force of said spring, thereby to close said valve, said means including handles projecting through the slots in said housing for manual actuation of said means, the remainder of said means being within said housing andprotected thereby.

19. In a combined carbide hopper and feed control unit for an acetylene generator in which the hopper is provided with a carbide feed opening in its lower end toward which the interior wall surfaces of said hopper converge for accumulating carbide adjacent said opening, the combination of a carbide feed valve rod having an annular notch formed therein near the lower end thereof and adapted to cooperate with said opening for controlling the flow of carbide therethrough, said rod above and below said notch being of uniform cross section adapted to fit said opening, pressure responsive mechanism including a diaphragm for actuating said rod in accordance with variations of acetylene pressure within the generator, and a lug on the side of the struction to the passage of said rod through said accumulated carbide, whereby said rod may deleased by said reverse operation of said manually operable means, to move said carbide feed valve without moving said manually operable means,

scend rapidly and the upper uniform cross section thereof may close said carbide feed opening promptly in the event that said rod breaks or becomes disconnected from said diaphragm.

WILLIS G. SCHEPMAN. 

